The relates to a flow indicator or flowmeter with an impeller rotatably mounted in an essentially circular-cylindrical flow chamber of a flow housing which has an inlet channel and an outlet channel.
Flow indicators or flowmeters of this type are known. They yield a direct indication of flow in that the impeller, which rotates with the flow, is visible from the side, or they serve as flowmeters, counters and metering devices in that the impeller is equipped with alternately polarized magnets at the ends of the impeller blades. The magnets trigger voltage impulses in a fixed position pick-up coil. These electric impulses can be amplified and counted in an electronic circuit, from which the quantity of flow (or flow rate) is determined and displayed on a display panel by means of light-emitting diodes in units of, for example, liters or liters per minute. Such impeller flow indicators or meters have, for example, with respect to some floating member flow meters, the advantage of almost viscosity-independent indication or measurement results. However, the period for which this type of existing device will operate reliably is relatively limited, and as a flowmeter which requires a housing for the electric circuit, this kind of device requires significant space. Furthermore, its flow resistance is relatively large since the inlet channel and the outlet channel are in one and the same side wall.